Dimensional precision of implant-supported frameworks fabricated by 3D printing

Author(s)

Camacho Presotto, Anna Gabriella ^[1] ; Ricardo Barao, Valentim Adelino ^[1] ; Brilhante Bhering, Claudia Lopes ^[2] ; Mesquita, Marcelo Ferraz ^[1]

Affiliation

^[1] Univ Estadual Campinas, Piracicaba Dent Sch, Dept Prosthodont & Periodontol, UNICAMP, Av Limeira 901, BR-13414903 Piracicaba, SP - Brazil

^[2] Fed Univ Minas Gerais UFMG, Sch Dent, Dept Restorat Dent, Belo Horizonte, MG - Brazil

• Document type: Journal article
• Source: JOURNAL OF PROSTHETIC DENTISTRY; v. 122, n. 1, p. 38-45, JUL 2019.
• Web of Science Citations: 0

Abstract

Statement of problem. Selective laser melting (SLM) is a promising additive technology for clinical practice, but data on dimensional precision assessed by marginal fit combined with stress and strain investigations of implant-supported fixed partial dentures (FPDs) are lacking. Purpose. The purpose of this in vitro study was to verify whether the SLM additive manufacturing technology provides better dimensional precision for 3-unit FPD frameworks than subtractive manufacturing with soft metal block (SMB) milling and the standard casting technique. Material and methods. Thirty 3-unit implant-supported FPDs with Co-Cr frameworks were made by the casting, SMB milling, and SLM methods (n=10). The marginal fit between the framework and the implant abutment was evaluated with photoelastic (PH) and strain gauge (SG) models. Stress and strain in the implant-supported system were measured by quantitative PH and SG analyses after prosthetic screw tightening. Data were subjected to the Kruskal-Wallis test, Mann-Whitney U test, and Spearman correlation test (alpha=.05). Results. The framework manufacturing method affected the marginal fit (P<.001), stress, and strain values (P<.05). The SLM group showed the best mean +/- standard deviation marginal fit (mu m) (PH model: 8.4 +/- 3.2; SG model: 6.9 +/- 2.1) in comparison with SMB milling (PH model: 42.3 +/- 15.7; SG model: 41.3 +/- 15.3) and casting (PH model: 43.5 +/- 27.8; SG model: 41.3 +/- 24.6) (P<.05). SLM showed lower mean +/- standard deviation stress and strain values (60.3 +/- 11.6 MPa; 91.4 +/- 11.1 mu strain) than casting (225.5 +/- 142.8 MPa; 226.95 +/- 55.4 mu strain) and SMB milling (218.6 +/- 101.7 MPa; 289.7 +/- 89.3 mu strain) (P<.05). A positive correlation was observed between fit and stress or strain for all groups (P<.05). Conclusions. Three-unit FPD frameworks made using the SLM technology showed better dimensional precision than those obtained with the casting or SMB milling methods. (AU)

• FAPESP's process: 16/23490-1 - Using Selective Laser Melting additive CAD/CAM technology (3D printing) for the fabrication of implant-supported partial fixed dental prosthesis: biomechanical, structural and electrochemical analysis
• Grantee: Anna Gabriella Camacho Presotto
• Support Opportunities: Scholarships in Brazil - Doctorate